Both of the leads in the French action flick DISTRICT B13 practice parkour, a kind of urban gymnastics that looks a little like skateboarding without the skateboard, and the pleasure of this short frenetic film is watching the two lithe heroes leap through windows, run up walls, and jump off buildings. Like Jackie Chan, Cyril Raffaelli, and David Belle, both stuntmen-turned-leading-men perform their own acrobatic martial arts sans special effects or invisible wires, and the lo-fi fight sequences pack a gritty punch that is often missing in slick Hollywood fare. The plot involves a futuristic France where the worst ghettos have been walled off from the rest of society, their schools shut down, and the police force evacuated. The people in power simply want to ignore the plight of the disenfranchised, but this becomes difficult to do when the most notorious gang, led by the wild-eyed Taha (Bibi Naceri), gets its hands on a nuclear warhead and proceeds to demand a 20-million-Euro ransom, with the city of Paris as its hostage. Enter Damien (Raffaelli), a one-man police strike force, who has 24 hours to disarm the missile. To help him navigate the war zone of District B13, he springs a vigilante antihero, Leito (Belle), from jail. Leito has personal reasons for taking down the crime lord: Taha has turned Leito's adolescent sister into his junkie pet. As the ultra-athletic duo go up against Taha's gangster army, they repeatedly (and conveniently) lose their guns, and are forced to improvise, thrashing goons with steering wheels, cinder blocks, and their foreheads. The screenplay (written by Luc Besson, director of LA FEMME NIKITA) and the blunt political critique are a bit heavy-handed, but obviously that's beside the point. Lovers of action flicks could ignore the English subtitles completely and still relish the hyperkinetic beauty of the whip-quick combat.